69CapriceHDTP

Have a 6.0 with an S475 only at 500rwhp at the moment in a 69 Caprice. Harness was originally a 4L60 harness but was changed over to the 80 and the tuner changed programming over to 4L80 as well. I got about 5 dyno pulls and 10-20 miles on the freshly rebuilt 4L80 which was built by a reputable guy that builds lots of race transmissions. Has an FTI converter and the drive gear ground itself into the pump and wiped out the whole transmission. I sent the converter off to FTI to check it out and had the entire transmission gone through again. FTI claims the converter is fine after cutting it open, inspecting and measuring everything. I put it all back together and took it for a 10 mile drive and put it back up on the hoist. I dropped a little trans fluid and its got metal shavings in it already. The converter slides roughly 1/4" out of trans and I noticed it bottomed out on the flex plate bolts (stock 6.0 flexplate with shim) and pulled maybe 1/8" on the flexplate. Never noticed this before but FTI claims I got same converter back. They told me it can only slide out of trans 1/8" and the rest must be shimmed and that could be causing the issue. I pulled engine out of car and tore it down to inspect Thrust bearing on crank and that is in perfect shape so the crank is not walking either. Any help would be appreciated. Thanks!!!

forcd ind

iTrader: (7)

What exactly is your FW setup-if its a stock 60E FW(curved), are you using the round spacer?
If its an 80E FW (flat) are you using the .400 spacer bet the crank and FW?
Did FTI make the converter based off an 80E conv., or a 60E with the longer snout-you have a mismatch of parts somewhere.
I have used FTI convs. with no problem-with the converter in all the way, you shouldn't have much more than .120 pullout to meet the conv. pads, an the conv. snout should reg. into the crank/spacer a little bit

69CapriceHDTP

Using stock 05 6.0 4L80 Flexplate with spacer. Converter was built for 4L80. It has a long snout but does not bottom out in the crank.

jakeshoe

iTrader: (14)

Inner pump gear ground into the pump is improper converter installation. Nothing else can push the gear into the pump.

69CapriceHDTP

converter goes all the way in. When I pull it up to the flex plate it still spins freely before tightening bolts. So where exactly am I not knowing how to install?

69CapriceHDTP

Lines were flushed very well. There is a lot of filings, not just a little. I'm lost on the tuning part, can you explain that more in depth.

jakeshoe

iTrader: (14)

When the pump eats itself, it makes a lot of metal filings. Iron from the pump.
The gears are billet steel. So unlike a Powerglide,TH400, TH350, or 4L60 they don't easily break when the converter is installed wrong. The converter pushes the inner gear into the cover and makes it's own clearance. Filling the converter, transmission, and cooler with metal.

There is simply no other cause for that except the gear wasn't properly engaged on the converter.
Nothing else can push the gear rearward except extreme crank thrust movement or converter ballooning. Both of which would be evident during a post failure analysis.

I see it happen and of course the answer is always that the customer or installer didn't make a mistake, they've done it 100 times, etc, etc.

I have yet to hear a reasonable explanation of what else can push the inner gear backwards hard enough to eat into iron.

truckdoug

iTrader: (25)

i had my pump gears in backwards and it would do something similar. it would bolt up, but kind of bind. pull that pump out and double check which way the flats are facing.

http://www.transmissionpartsusa.com/...34201ESP-2.jpg

the dots should face towards the front of the car